Frequency hopping communication method and device

ABSTRACT

In certain embodiments, a method includes receiving, by a terminal device, a plurality of virtual channel indexes from a base station and selecting, by the terminal device, a virtual channel index from the plurality of virtual channel indexes. The method further includes determining, by the terminal device based on the virtual channel index, physical channels corresponding to the virtual channel index on a plurality of subframes. At least two of the physical channels corresponding to the virtual channel index on the plurality of subframes are different. The method further includes communicating, by the terminal device on at least one of the plurality of subframes, with the base station using the physical channel corresponding to the virtual channel index.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/422,453, filed on May 24, 2019, which is a continuation ofInternational Application No. PCT/CN2017/103133, filed on Sep. 25, 2017.The International Application claims priority to Chinese PatentApplication No. 201611071905.3, filed on Nov. 29, 2016. All of theafore-mentioned patent applications are hereby incorporated by referencein their entireties.

TECHNICAL FIELD

The embodiments of the present invention relate to the communicationsfield, and in particular, to a frequency hopping communication methodand a device.

BACKGROUND

The mobile Internet industry and the Internet of Things industry havedeveloped rapidly, and an Internet of Things network device is low-cost,easy to deploy, and maintenance-free. In an enterprise market, maincommunication requirements of enterprise Internet of Things are a smallamount of data and mass connections. Compared with a licensed spectrumof an operator, an unlicensed spectrum, especially a frequency band ofSub GHz, can effectively reduce network costs. Therefore, a narrowbandcommunications system based on the unlicensed spectrum can meet therequirements.

Each region in each country has corresponding regulations on theunlicensed spectrum, so as to prevent all devices from irregularly andlimitlessly sending data on the unlicensed spectrum. Before accessing anetwork, a device needs to be certified by regulations of each country.In other words, any device may not monitor a channel before sendingdata, but needs to meet a specific sending duty cycle; that is, totalsending time of the device cannot exceed a threshold within a specifictime.

In order to meet a requirement of regulations on the duty cycle, twotechnical means are commonly used in the unlicensed frequency band: oneis Listen Before Talk (LBT), that is, any device needs to monitor thechannel before sending data; and the other is frequency hopping, thatis, after sending the data on a channel for a period of time, the deviceswitches to another frequency band to use another channel. Frequencyhopping in a Bluetooth technology is used as an example. Bluetooth is ashort-range wireless communications technology operating on an ISMfrequency band of 2.4 GHz (2.40 to 2.48 GHz), and can form a smallwireless personal access network (PAN). Bluetooth uses a series ofunique measures such as Adaptive Frequency Hopping (AFH), LBT, and powercontrol to overcome interference and avoid conflicts.

However, Bluetooth uses a time division multiple access technology, anda central device cannot communicate with a plurality of secondarydevices at a same time point, and therefore a Bluetooth primary devicecannot connect too many secondary devices at a same time point.Consequently, a requirement of the Internet of Things for massconnections cannot be met.

SUMMARY

Embodiments of the present invention provide a frequency hoppingcommunication method and a device, so as to determine, in a narrowbandsystem of an unlicensed spectrum, a physical channel used for frequencyhopping.

A first aspect of the embodiments of the present invention provides afrequency hopping communication method, where the method includes:

-   -   receiving, by a terminal device, a plurality of virtual channel        indexes from a base station, and optionally, receiving, by the        terminal device, the plurality of virtual channel indexes from        the base station using a broadcast message or a dedicated        message.

Therefore, the terminal device selects a virtual channel index from avirtual channel index set. It should be noted that a plurality ofterminal devices may select different virtual channel indexes from thevirtual channel index set. Optionally, the terminal device may furtherreceive a physical cell identifier, a configuration parameter of aquantity of system channels, a frame number, a subframe number, and asuper frame number, and determine, based on the virtual channel indexand one or any combination of the foregoing parameters, physicalchannels corresponding to the virtual channel index on a plurality ofsubframes.

A virtual channel index may be used to determine physical channelscorresponding to the virtual channel index on the plurality ofsubframes, and because of a restriction of regulations, at least two ofthe physical channels corresponding to the virtual channel index on theplurality of subframes are different. Further, because frequency hoppingis required, frequency hopping may be performed once after communicationis performed on each subframe. That is, in the physical channelscorresponding to the plurality of virtual channel indexes on theplurality of subframes, physical channels corresponding to a samevirtual channel index on two adjacent subframes are different.

After determining the physical channel corresponding to the virtualchannel index on each subframe, the terminal device may communicate, onat least one of the plurality of subframes, with the base station usingthe physical channel corresponding to the virtual channel index.Optionally, communication may be performed on all of the plurality ofsubframes using the physical channel corresponding to the virtualchannel index.

On a subframe, the base station may simultaneously communicate with theplurality of terminal devices. Compared with a Bluetooth technology,under a same condition, a quantity of the terminal devices thatcommunicate with a base station is greatly increased, and therefore, arequirement of the Internet of Things for mass connections can becorrespondingly met.

With reference to the first aspect, in a first implementation of thefirst aspect of the embodiments of the present invention, a detailedmethod of determining calculation of the physical channel may include:

-   -   inputting the virtual channel index and any subframe S in the        plurality of subframes, where a number of the subframe S        includes a super frame number, a frame number, and a subframe        number; and further inputting a physical cell identifier and a        configuration parameter of a quantity of system channels for        calculation. Specifically, the terminal device calculates the        physical cell identifier and the S using a preset algorithm, to        obtain a first value T1 of four bits, then performs bit        reordering on the T1 to obtain a second value T2 of four bits,        then calculates the T2 and the S to obtain a third decimal value        T3, and then calculates the T3 and the virtual channel index to        obtain a physical channel related to the virtual channel index,        the physical cell identifier, and the configuration parameter of        the quantity of system channels.

Because the plurality of virtual channel indexes are disorderedaccording to a specific rule, a corresponding physical channel thatmeets randomicity and orthogonality may be obtained.

A second aspect of the embodiments of the present invention provides afrequency hopping communication method, where the method includes:

-   -   generating, by a base station, a plurality of virtual channel        indexes, and optionally, sending, by the base station, the        plurality of generated virtual channel indexes to a plurality of        terminal devices using a broadcast message or a dedicated        message.

Optionally, the base station may further generate and send a physicalcell identifier, a configuration parameter of a quantity of systemchannels, a frame number, a subframe number, and a super frame number,and determine, based on the virtual channel index and one or anycombination of the foregoing parameters, physical channels correspondingto the virtual channel index on a plurality of subframes.

A virtual channel index may be used to determine physical channelscorresponding to the virtual channel index on the plurality ofsubframes, and because of a restriction of regulations, at least two ofthe physical channels corresponding to the virtual channel index on theplurality of subframes are different. Further, because frequency hoppingis required, frequency hopping may be performed once after communicationis performed on each subframe. That is, in the physical channelscorresponding to the plurality of virtual channel indexes on theplurality of subframes, physical channels corresponding to a samevirtual channel index on two adjacent subframes are different.

Because physical channels corresponding to the virtual channel index onadjacent subframes are different, after communication is performed oneach subframe, the terminal device performs frequency hopping, and thismeets a requirement of related regulations.

Then, based on any virtual channel index D in the plurality of virtualchannel indexes, the base station may determine a physical channelcorresponding to the D on each of the plurality of subframes, where atleast two of the physical channels corresponding to the D on differentsubframes are different. Further, in the physical channels correspondingto the plurality of virtual channel indexes on the plurality ofsubframes, physical channels corresponding to a same virtual channelindex on two adjacent subframes are different.

It should be noted that, when selecting the D, the terminal device usesa calculation method that is the same as a calculation method used bythe base station, and a same physical channel on a same subframe isobtained, and then the physical channel is used for communicationbetween the terminal device and the base station on the subframe.

Optionally, when the base station determines the physical channel,physical channels corresponding to any two of the plurality of virtualchannel indexes on a subframe are different, and orthogonality is met.

Further, in some feasible embodiments, a virtual channel index iscorresponding to a subframe group, and subframe groups corresponding totwo virtual channel indexes may be different. If subframe groupscorresponding to two different virtual channel indexes have anoverlapping subframe, physical channels corresponding to the twodifferent virtual channel indexes on the subframe are also different.

Because the physical channels corresponding to any two virtual channelindexes on the subframe are different, an obtained physical channelcorresponding to a virtual channel index on each subframe may meetorthogonality. Therefore, a channel resource is fully used, so that abase station can communicate with as many terminal devices as possible.

After determining the physical channel corresponding to the virtualchannel index on each subframe, the base station may communicate, on aplurality of subframes, with the plurality of terminal devices using thephysical channel corresponding to the virtual channel index.

On a subframe, the base station may simultaneously communicate with theplurality of terminal devices. Compared with a Bluetooth technology,under a same condition, a quantity of terminal devices that communicatewith a base station is greatly increased, and therefore, a requirementof the Internet of Things for mass connections can be correspondinglymet.

With reference to the second aspect, in a first implementation of thesecond aspect of the embodiments of the present invention, the methodincludes:

-   -   inputting the virtual channel index and any subframe S in the        plurality of subframes, where a number of the subframe S        includes a super frame number, a frame number, and a subframe        number; and further inputting a physical cell identifier and a        configuration parameter of a quantity of system channels for        calculation. Specifically, the base station may further        calculate the physical cell identifier and the S using a preset        algorithm, to obtain a first value T1 of four bits, then        performs bit reordering on the T1 to obtain a second value T2 of        four bits, then calculates the T2 and the S to obtain a third        decimal value T3, and then calculates the T3 and the virtual        channel index to obtain a physical channel related to the        virtual channel index, the physical cell identifier, and the        configuration parameter of the quantity of system channels.

Because the plurality of virtual channel indexes are disorderedaccording to a specific rule, a corresponding physical channel thatmeets randomicity and orthogonality may be obtained.

A third aspect of the embodiments of the present invention provides afrequency hopping communication method, where the method includes:

-   -   generating, by a base station, a plurality of virtual channel        indexes, and optionally, sending, by the base station, the        plurality of generated virtual channel indexes to a plurality of        terminal devices using a broadcast message or a dedicated        message.

Optionally, the base station may further generate and send a physicalcell identifier, a configuration parameter of a quantity of systemchannels, a frame number, a subframe number, and a super frame number,and determine, based on the virtual channel index and one or anycombination of the foregoing parameters, physical channels correspondingto the virtual channel index on a plurality of subframes.

A virtual channel index may be used to determine physical channelscorresponding to the virtual channel index on the plurality ofsubframes, and because of a restriction of regulations, at least two ofthe physical channels corresponding to the virtual channel index on theplurality of subframes are different. Further, because frequency hoppingis required, frequency hopping may be performed once after communicationis performed on each subframe. That is, in the physical channelscorresponding to the plurality of virtual channel indexes on theplurality of subframes, physical channels corresponding to a samevirtual channel index on two adjacent subframes are different.

Because physical channels corresponding to the virtual channel index onadjacent subframes are different, after communication is performed oneach subframe, the terminal device performs frequency hopping, and thismeets a requirement of related regulations.

The base station may determine, based on any virtual channel index D inthe plurality of virtual channel indexes, a physical channelcorresponding to the D on each of the plurality of subframes. When thebase station determines the physical channel, physical channelscorresponding to any two of the plurality of virtual channel indexes ona subframe are different, and orthogonality is met. Further, in somefeasible embodiments, a virtual channel index is corresponding to asubframe group, and subframe groups corresponding to two virtual channelindexes may be different. If subframe groups corresponding to twodifferent virtual channel indexes have an overlapping subframe, physicalchannels corresponding to the two different virtual channel indexes onthe subframe are also different.

Because the physical channels corresponding to any two virtual channelindexes on the subframe are different, an obtained physical channelcorresponding to a virtual channel on each subframe may meetorthogonality. Therefore, a channel resource is fully used, so that abase station can communicate with as many terminal devices as possible.

Further, in some feasible embodiments, a virtual channel index iscorresponding to a subframe group, and subframe groups corresponding totwo virtual channel indexes may be different. If subframe groupscorresponding to two different virtual channel indexes have anoverlapping subframe, physical channels corresponding to the twodifferent virtual channel indexes on the subframe are also different.

Because the physical channels corresponding to any two virtual channelindexes on the subframe are different, an obtained physical channelcorresponding to a virtual channel on each subframe may meetorthogonality. Therefore, a channel resource is fully used, so that abase station can communicate with as many terminal devices as possible.

Because the physical channels corresponding to any two virtual channelindexes on the subframe are different, an obtained physical channelcorresponding to a virtual channel on each subframe may meetorthogonality. Therefore, a channel resource is fully used, so that abase station can communicate with as many terminal devices as possible.

After determining the physical channel corresponding to the virtualchannel index on each subframe, the base station may communicate, on aplurality of subframes, with the plurality of terminal devices using thephysical channel corresponding to the virtual channel index.

On a subframe, the base station may simultaneously communicate with theplurality of terminal devices. Compared with a Bluetooth technology,under a same condition, a quantity of terminal devices that communicatewith a base station is greatly increased, and therefore, a requirementof the Internet of Things for mass connections can be correspondinglymet.

With reference to the third aspect, in a first implementation of thethird aspect of the embodiments of the present invention, the methodincludes that:

-   -   for the virtual channel index D in the plurality of virtual        channel indexes and any subframe S in the plurality of        subframes, the base station calculates the D and the S to obtain        a first value T1, where the TI is a value of four bits; the base        station performs bit reordering on values of four bits of the T1        using a preset algorithm, to obtain a second value T2, where the        T2 is a value of four bits; the base station calculates the T2        and the S using the preset algorithm, to obtain a third value        T3; and the base station calculates the T3 and the D using the        preset algorithm, to obtain a physical channel corresponding to        the D on the S.

Because the plurality of virtual channel indexes are disorderedaccording to a specific rule, a corresponding physical channel thatmeets randomicity and orthogonality may be obtained.

A fourth aspect of the embodiments of the present invention provides aterminal device, where the terminal device includes:

-   -   a transceiver unit, configured to receive a plurality of virtual        channel indexes from a base station; and a processing unit,        configured to select a virtual channel index from the plurality        of virtual channel indexes, and determine, based on the virtual        channel index, physical channels corresponding to the virtual        channel index on a plurality of subframes, where at least two of        the physical channels corresponding to the virtual channel index        on the plurality of subframes are different. The transceiver        unit is further configured to communicate, on at least one of        the plurality of subframes, with the base station using the        physical channel corresponding to the virtual channel index.

On a subframe, the base station may simultaneously communicate with theplurality of terminal devices. Compared with a Bluetooth technology,under a same condition, a quantity of terminal devices that communicatewith a base station is greatly increased, and therefore, a requirementof the Internet of Things for mass connections can be correspondinglymet.

Optionally, the plurality of virtual channel indexes are received fromthe base station using a broadcast message or a dedicated message.

With reference to the fourth aspect, in a first implementation of thefourth aspect of the embodiments of the present invention, theprocessing unit is configured to:

-   -   for the virtual channel index and any subframe S in the        plurality of subframes, calculate a physical cell identifier and        the S using a preset algorithm, to obtain a first value T1,        where the TI is a value of four bits; perform bit reordering on        values of four bits of the T1 using the preset algorithm, to        obtain a second value T2, where the T2 is a value of four bits;        calculate the T2 and the S using the preset algorithm, to obtain        a third value T3; and calculate the T3 and the virtual channel        index using the preset algorithm, to obtain a physical channel        corresponding to the virtual channel index on the S.

A fifth aspect of the embodiments of the present invention provides abase station, where the base station includes:

-   -   a transceiver unit, configured to send a plurality of generated        virtual channel indexes; and a processing unit, configured to:        for any virtual channel index D in the plurality of virtual        channel indexes, determine, based on the D, a physical channel        corresponding to the D on each of the plurality of subframes,        where at least two of the physical channels corresponding to the        D on different subframes are different, and determine a virtual        channel index selected by a terminal device, where the virtual        channel index is one of the plurality of virtual channel        indexes. The transceiver unit is further configured to        communicate, on at least one of the plurality of subframes, with        the terminal device using the physical channel corresponding to        the virtual channel index.

On a subframe, the base station may simultaneously communicate with theplurality of terminal devices. Compared with a Bluetooth technology,under a same condition, a quantity of terminal devices that communicatewith a base station is greatly increased, and therefore, a requirementof the Internet of Things for mass connections can be correspondinglymet.

Optionally, the processing unit is further configured to:

-   -   determine, based on each of the plurality of virtual channel        indexes, a physical channel corresponding to each virtual        channel index on a subframe, where the physical channels        corresponding to any two of the plurality of virtual channel        indexes on the subframe are different.

Optionally, the processing unit is further configured to:

-   -   based on a subframe group corresponding to each of the plurality        of virtual channel indexes, for any virtual channel index D in        the plurality of virtual channel indexes, determine, based on        the D, a physical channel corresponding to the D on each        subframe in a subframe group corresponding to the D, where        physical channels corresponding to any two of the plurality of        virtual channel indexes on a same subframe are different.

A sixth aspect of the embodiments of the present invention provides abase station, where the base station includes:

-   -   a transceiver unit, configured to send a plurality of generated        virtual channel indexes; and a processing unit, configured to        determine, based on each of the plurality of virtual channel        indexes, a physical channel corresponding to each virtual        channel index on a subframe, where physical channels        corresponding to any two of the plurality of virtual channel        indexes on the subframe are different, and determine a virtual        channel index selected by a terminal device, where the virtual        channel index is one of the plurality of virtual channel        indexes. The transceiver unit is further configured to        communicate, on the subframe, with the terminal device using a        physical channel corresponding to the virtual channel index.

On a subframe, the base station may simultaneously communicate with theplurality of terminal devices. Compared with a Bluetooth technology,under a same condition, a quantity of terminal devices that communicatewith a base station is greatly increased, and therefore, a requirementof the Internet of Things for mass connections can be correspondinglymet.

Optionally, the processing unit is further configured to:

-   -   based on a subframe group corresponding to each of the plurality        of virtual channel indexes, for any virtual channel index D in        the plurality of virtual channel indexes, determine, based on        the D, a physical channel corresponding to the D on each        subframe in a subframe group corresponding to the D, where        physical channels corresponding to any two of the plurality of        virtual channel indexes on a same subframe are different.

Optionally, the processing unit is further configured to:

-   -   for any virtual channel index D in the plurality of virtual        channel indexes, determine, based on the D, a physical channel        corresponding to the D on each of the plurality of subframes,        where at least two of the physical channels corresponding to the        D on different subframes are different.

Optionally, the transceiver unit is further configured to:

-   -   send the plurality of generated virtual channel indexes using a        broadcast message or a dedicated message.

With reference to the sixth aspect, in a first implementation of thesixth aspect of the embodiments of the present invention, the processingunit is further configured to:

-   -   for the virtual channel index and any subframe S in the        plurality of subframes, calculate a physical cell identifier and        the S using a preset algorithm, to obtain a first value T1,        where the TI is a value of four bits; perform bit reordering on        values of four bits of the T1 using the preset algorithm, to        obtain a second value T2, where the T2 is a value of four bits;        calculate the T2 and the S using the preset algorithm, to obtain        a third value T3; and calculate the T3 and the virtual channel        index using the preset algorithm, to obtain a physical channel        corresponding to the virtual channel index on the S.

A seventh aspect of the embodiments of the present invention provides aterminal device, where the terminal device includes:

-   -   a transceiver and a processor. The transceiver is configured to        receive a plurality of virtual channel indexes from a base        station. The processor is configured to: select a virtual        channel index from the plurality of virtual channel indexes, and        determine, based on the virtual channel index, physical channels        corresponding to the virtual channel index on a plurality of        subframes, where at least two of the physical channels        corresponding to the virtual channel index on the plurality of        subframes are different. The transceiver is further configured        to communicate, on at least one of the plurality of subframes,        with the base station using the physical channel corresponding        to the virtual channel index.

An eighth aspect of the embodiments of the present invention provides abase station, where the base station includes:

-   -   a transceiver and a processor. The transceiver is configured to        send a plurality of generated virtual channel indexes.

The processor is configured to: for any virtual channel index D in theplurality of virtual channel indexes, determine, based on the D, aphysical channel corresponding to the D on each of the plurality ofsubframes, where at least two of the physical channels corresponding tothe D on different subframes are different; and determine a virtualchannel index selected by a terminal device, where the virtual channelindex is one of the plurality of virtual channel indexes. Thetransceiver is further configured to communicate, on at least one of theplurality of subframes, with the terminal device using the physicalchannel corresponding to the virtual channel index.

A ninth aspect of the embodiments of the present invention provides abase station, where the base station includes:

-   -   a transceiver and a processor. The transceiver is configured to        send a plurality of generated virtual channel indexes. The        processor is configured to: determine, based on each of the        plurality of virtual channel indexes, a physical channel        corresponding to each virtual channel index on a subframe, where        physical channels corresponding to any two of the plurality of        virtual channel indexes on the subframe are different; and        determine a virtual channel index selected by a terminal device,        where the virtual channel index is one of the plurality of        virtual channel indexes. The transceiver is further configured        to communicate, on the subframe, with the terminal device using        a physical channel corresponding to the virtual channel index.

It can be learned from the foregoing technical solutions that theembodiments of the present invention have the following advantages:

The terminal device receives the plurality of virtual channel indexesfrom the base station; the terminal device selects a virtual channelindex from the plurality of virtual channel indexes; the terminal devicedetermines, based on the virtual channel index, the physical channelscorresponding to the virtual channel index on a plurality of subframes,where at least two of the physical channels corresponding to the virtualchannel index on the plurality of subframes are different; and theterminal device communicates, on at least one of the plurality ofsubframes, with the base station using the physical channelcorresponding to the virtual channel index. Therefore, the base stationmay simultaneously communicate with a plurality of terminal devices on asubframe. Compared with a Bluetooth technology, under a same condition,a quantity of the terminal devices that communicate with a base stationis greatly increased, so that a requirement of the Internet of Thingsfor mass connections can be correspondingly met.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic architectural diagram of a frequency hoppingcommunications system according to an embodiment of the presentinvention;

FIG. 2 is a schematic flowchart of an embodiment of a frequency hoppingcommunication method according to an embodiment of the presentinvention;

FIG. 3 is a schematic flowchart of an embodiment of determining aphysical channel on a subframe based on a virtual channel indexaccording to an embodiment of the present invention;

FIG. 4 is a schematic diagram of an embodiment of a terminal deviceaccording to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an embodiment of a base stationaccording to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an embodiment of a base stationaccording to an embodiment of the present invention;

FIG. 7 is a schematic diagram of an embodiment of a terminal deviceaccording to an embodiment of the present invention;

FIG. 8 is a schematic diagram of an embodiment of a base stationaccording to an embodiment of the present invention; and

FIG. 9 is a schematic diagram of an embodiment of a base stationaccording to an embodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Embodiments of the present invention provide a frequency hoppingcommunication method and a device, so as to determine, in a narrowbandsystem of an unlicensed spectrum, a physical channel used for frequencyhopping.

In the specification, claims, and accompanying drawings of the presentinvention, the terms “first”, “second”, “third”, “fourth”, and so on (ifany) are intended to distinguish between similar objects but do notnecessarily indicate a specific order or sequence. It should beunderstood that the data termed in such a way are interchangeable inproper circumstances so that the embodiments described herein can beimplemented in other orders than the order illustrated or describedherein. In addition, the terms “include”, “contain” and any othervariants mean to cover the non-exclusive inclusion, for example, aprocess, method, system, product, or device that includes a list ofsteps or units is not necessarily limited to those steps or units, butmay include other steps or units not expressly listed or inherent tosuch a process, method, system, product, or device.

FIG. 1 is a schematic architectural diagram of a frequency hoppingcommunications system. The frequency hopping communications system isused in a narrowband system of an unlicensed spectrum, and includes abase station and a plurality of terminal devices.

With development of the mobile Internet industry and the Internet ofThings industry, increasing mobile terminal devices are connected toeach other and share more abundant data. Facing an enterprise market, anInternet of Things network device is low-cost, easy to deploy, andmaintenance-free. Compared with a licensed spectrum of an operator,network costs can be effectively reduced on the unlicensed spectrum,especially on a frequency band of Sub GHz, and main communicationrequirements of enterprise Internet of Things are a small amount of dataand mass connections. Therefore, a narrowband communications systembased on the unlicensed spectrum can meet this requirement.

In the embodiments of the present invention, the base station refers toa public mobile communications base station, which is a form of a radiostation and refers to a radio transceiver station that transfersinformation to a mobile phone terminal device in a specific radiocoverage area using a mobile communications switching center.

In some feasible embodiments, the base station may include a basebandunit BBU and a radio remote unit RRU, where the RRU is connected to anantenna feeder system (antenna).

The terminal device used in the embodiments of the present invention maybe a device that provides a user with voice and/or data connectivity, ahandheld device with a radio connection function, or another processingdevice connected to a wireless modem. A wireless terminal device maycommunicate with one or more core networks using a radio access network(RAN). The wireless terminal device may be a mobile terminal device suchas a mobile phone (or referred to as a “cellular” phone), or a computerwith a mobile terminal device, for example, a portable, pocket-sized,handheld, computer built-in, or in-vehicle mobile apparatus thatexchanges voice and/or data with the radio access network. For example,the wireless terminal device may be a device such as a personalcommunication service (PCS) phone, a cordless telephone set, a SessionInitiation Protocol (SIP) phone, a wireless local loop (WLL,) station,or a personal digital assistant (PDA). The wireless terminal device mayalso be referred to as a system, a subscriber unit, a subscriber station(Subscriber Station), a mobile station, a mobile console (Mobile), aremote station, an access point, a remote terminal device, an accessterminal device, a user terminal device, a terminal device, a useragent, user device, or user equipment.

Specifically, a mobile phone is used as an example. The terminal devicemay include components such as a radio frequency (RF) circuit, a memory,an input unit, a display unit, a sensor, an audio circuit, a WirelessFidelity (Wi-Fi) module, a processor, and a power supply. A personskilled in the art may understand that the structure of the mobile phoneimposes no limitation on the mobile phone, and the mobile phone mayinclude more or fewer components, or combine some components, or havedifferent component arrangements, and this is not limited herein.

In some feasible embodiments, the present invention may be used in anetwork with a star topology. Each node in the network is connected to acentral node (also referred to as a central transfer station, which isgenerally a hub or a switch) in a point-to-point manner, and the centralnode transmits information to a destination node. The central nodeimplements a centralized communication control policy. Therefore, thecentral node is rather complex and bears a much heavier burden than eachnode. Communication between any two nodes in the star network needs tobe controlled by the central node.

The network with a star topology is a centralized control network. Theentire network is managed by performing centralized access control bythe central node, and the nodes communicate with each other through thecenter node. Each node that needs to send data sends the data to acentral node, and the central node is responsible for sending the datato the destination node. Therefore, the central node is rather complex,a communication processing burden of each node is very light, and eachnode only needs to meet a simple communication requirement of a link.

Because the central node needs to connect to a plurality of devices andthere are many lines, to facilitate centralized connection, a hub (HUB)or a switching device is used as the central node. Generally, a networkenvironment is designed as a star topology structure. The star networkis one of the most widely used and preferred network topology designs.

In the embodiments of the present invention, each region in each countryhas corresponding regulations on the unlicensed spectrum, so as toprevent all devices from irregularly and limitlessly sending data on theunlicensed spectrum. For example, the Federal Communications Commission(FCC) is directly responsible to the Congress, coordinates national andinternational communications by controlling radio broadcasting,television, telecommunications, satellites, and cables, and isresponsible for authorizing and managing radio frequency transmissionapparatuses and devices other than those used by the federal government.The FCC requires that a communications device meet a low duty cycle. Inother words, any device may not monitor a channel before sending data,but needs to meet a specific sending duty cycle; that is, total sendingtime of the device cannot exceed a threshold within a specific time. TheFCC 15.247 is used as an example. On frequency bands 902-928 MHz,2400-2483.5 MHz, and 5725-5850 MHz, to prevent one device from occupyinga channel for a long time, it is required that scheduling andnegotiation not be performed between devices.

Generally, in order to meet a requirement of regulations on the dutycycle, two technical means are commonly used in the unlicensed frequencyband: one is LBT, that is, any device needs to monitor the channelbefore sending data; and the other is frequency hopping technology(frequency hopping), that is, after sending the data on a channel for aperiod of time, the device switches to another frequency band to useanother channel. The FCC specifies frequency hopping indexes such as aquantity of frequency hopping channels, a duty cycle of a singlechannel, and frequency hopping bandwidth. Before accessing the network,the device needs to be certified by regulations of each country: InNorth America, FCC regulations are used; and in other countries,regulations based on the FCC regulations are used.

In the embodiments of the present invention, both the base station andthe terminal device are provided with a built-in frequency hoppingmodule, and the frequency hopping module uses a frequency hoppingtechnology for communication between the base station and the terminaldevice.

In some feasible embodiments, frequency hopping is one of the mostcommonly used spread spectrum manners. A working principle of thefrequency hopping is that a carrier frequency used for transmittingsignals by a receiving side and a sending side is changed discretelyaccording to a predetermined rule; that is, the carrier frequency usedfor communication randomly hops under control of a pseudo random changecode. A technology used for frequency hopping is referred to as afrequency hopping technology (FHSS), which means that the receiving sideand the sending side using a specific type of narrow-band carrier at thesame time to a non-specific receiver.

From an implementation of the communications technology, the frequencyhopping is a communication manner in which multi-frequency shift keyingis performed using a code sequence, and is also a code controlledcarrier frequency hopping communications system. In terms of timedomain, a frequency hopping signal is a multi-frequency shift keyingsignal. In terms of frequency domain, a frequency spectrum of thefrequency hopping signal randomly hops at unequal intervals on a verywide band. It should be noted that a frequency hopping controller is acore component, and includes functions such as frequency hopping patterngeneration, synchronization, and adaptive control. A frequency combinerobtains, through combination, a required frequency under control of thefrequency hopping controller. A data terminal device performs errorcontrol on the data.

With rapid development of the mobile Internet industry and the Internetof Things industry, the main communication requirements of theenterprise Internet of Things are a small amount of data and massconnections. Compared with a licensed spectrum, the unlicensed spectrumcan effectively reduce the network costs. However, there arecorresponding regulations on the unlicensed spectrum, so as to preventall devices from irregularly and limitlessly sending data on theunlicensed spectrum.

Two technical means are commonly used in an unlicensed frequency band:one is that any device needs to monitor the channel before sending thedata; and the other is the frequency hopping, that is, after sending thedata on a channel for a period of time, the device switches to anotherfrequency band to use another channel, for example, a Bluetoothtechnology. However, when communicating with a plurality of secondarydevices using the Bluetooth technology, a central device cannotcommunicate with the plurality of secondary devices at a same timepoint. Consequently, a requirement of the current Internet of Thingsindustry for mass connections cannot be met.

Therefore, in this embodiment of the present invention, the terminaldevice receives a plurality of virtual channel indexes from the basestation; the terminal device selects a virtual channel index from theplurality of virtual channel indexes; the terminal device determines,based on the virtual channel index, physical channels corresponding tothe virtual channel index on a plurality of subframes, where at leasttwo of the physical channels corresponding to the virtual channel indexon the plurality of subframes are different; and the terminal devicecommunicates, on at least one of the plurality of subframes, with thebase station using the physical channel corresponding to the virtualchannel index. Therefore, the base station may simultaneouslycommunicate with a plurality of terminal devices on a subframe. Under asame condition as a Bluetooth technology, a quantity of the terminaldevices that communicate with a base station is greatly increased, sothat a requirement of the Internet of Things for mass connections can becorrespondingly met.

For ease of understanding, a detailed procedure in this embodiment ofthis application is described below. FIG. 2 is a schematic flowchart ofan embodiment of a frequency hopping communication method according toan embodiment of the present invention. The method includes thefollowing steps.

201. A base station sends a plurality of generated virtual channelindexes.

In this embodiment of the present invention, a physical channel is avivid analogy of a path between a transmit end and a receive end inwireless communication. For a radio wave, there is no physicalconnection between the transmit end and the receive end, and there maybe more than one propagation path. To vividly describe work between thetransmit end and the receive end, it may be imagined that there is aninvisible road link between the transmit end and the receive end, andthis road link is referred to as a channel. Channel bandwidth limits alowest frequency and a highest frequency at which a signal is allowed topass the channel, and may be understood as a frequency passband.

In this embodiment of the present invention, in a network with a startopology, a plurality of terminal devices simultaneously perform uplinkservices at a same time, and for a frequency band of Sub GHz, the FCCregulation stipulates that a device cannot limitlessly occupy a channel,and therefore, a user needs to perform channel frequency hopping, and aseries of locations of frequency hopping channels that can be predictedby a real physical channel at different times according to a frequencyhopping rule is referred to as a virtual physical channel.

In some feasible embodiments, the base station may send the plurality ofvirtual channel indexes to the terminal device from the base stationusing a broadcast message or a dedicated message. The broadcast messageand the dedicated message are in the current system, and details are notdescribed herein.

202. A terminal device selects a virtual channel index from theplurality of virtual channel indexes.

In this embodiment of the present invention, when receiving theplurality of virtual channel indexes, the terminal device may select avirtual channel index from the plurality of virtual channel indexes, soas to use a virtual channel represented by the virtual channel index,and uses a physical channel corresponding to the virtual channel on eachsubframe to communicate with the base station.

203. The terminal device determines, based on the virtual channel index,physical channels corresponding to the virtual channel index on aplurality of subframes.

In some feasible embodiments, the terminal device may further determine,based on the virtual channel index and one or any combination of thefollowing: a physical cell identifier, a configuration parameter of aquantity of system channels, a frame number, a subframe number, or asuper frame number, the physical channels corresponding to the virtualchannel index on the plurality of subframes.

In some feasible embodiments, the physical cell identifier, that is,Physical Cell Identifier (PCI), is used by a terminal device in LTE todistinguish between radio signals of different cells. The LTE systemprovides 504 PCIs, which are conceptually similar to 128 scramblingcodes of a TD-SCDMA system. When configuration is performed using anetwork management system, a number between 0 and 503 is configured fora cell. In an LTE cell search procedure, a specific cell ID isdetermined by searching a primary synchronization sequence (PSS, andthere are three possibilities in total), a secondary synchronizationsequence (SSS, and there are 168 possibilities in total), or acombination of the primary synchronization sequence and the secondarysynchronization sequence. In this embodiment of the present invention,the PCI is described using 36 physical cells as an example, that is, avalue of the PCI is 0 to 35 in a decimal system, and 0 to 10011 in abinary system.

In some feasible embodiments, a number of the subframe includes thesuper frame number, the frame number, and the subframe number. One superframe includes eight frames, and one frame includes six subframes. In anarrowband Internet of Things system, there are 8192 super frames, andvalues of the 8192 super frames are 0 to 8191. The number of thesubframe may include 19 bits, where the super frame number includes 13bits, the frame number includes 3 bits, and the subframe number includes3 bits. On an unlicensed spectrum of the narrowband Internet of Thingssystem, total system bandwidth is 1.8 MHz, and is divided into ninechannels of 180 kHz and guard bandwidth of 180 kHz. The channel of 180kHz includes six sub-channels of 30 kHz. In system time domain, conceptsof an eSubframe, an eFrame (eFrame), and an eSuperframe are provided. Inthis embodiment, an example in which a subframe is 250 ms, a frameincludes six subframes, and a super frame includes eight frames is usedfor description.

In some feasible embodiments, the base station may further generate theconfiguration parameter of the quantity of system channels. Generally,the configuration parameter of the quantity of system channels may beseveral times of a quantity of physical channels, and is generally 6times the quantity of physical channels. Because one frame includes sixsubframes, if the configuration parameter of the quantity of systemchannels is 9, the quantity of physical channels is 9×6=54.

It should be noted that, in this embodiment of the present invention, atleast two of the physical channels corresponding to the virtual channelindex on the plurality of subframes are different. Due to limitation ofregulations, a physical channel in an unlicensed spectrum cannot serve aterminal device for a long time. Therefore, in this embodiment of thepresent invention, when communicating with the base station, a terminaldevice needs to switch from one physical channel to another physicalchannel. Therefore, when the terminal device selects a virtual channelindex, such regulations also need to be followed. The physical channelscorresponding to the virtual channel index on the plurality of subframescannot be all the same. Therefore, at least two physical channels needto be different, so that a requirement of the regulations is met.

Optionally, in the physical channels corresponding to the plurality ofvirtual channel indexes on the plurality of subframes, if physicalchannels corresponding to a same virtual channel index on two adjacentsubframes are different, a requirement of the regulations on frequencyhopping can be fully met.

It should be noted that, in some feasible embodiments, the virtualchannel index is generated by the base station, and the base stationgenerates the plurality of virtual channel indexes, where the virtualchannel index represents a virtual channel, and the virtual channel is aphysical channel on each subframe in a corresponding subframe group. Itshould be noted that a quantity of the plurality of virtual channelindexes is the same as the quantity of physical channels, and detailsare not described herein.

For a detailed calculation process, refer to FIG. 3. In some feasibleembodiments, an embodiment of determining the physical channel on thesubframe based on the virtual channel index includes the followingsteps.

2031. For the virtual channel index and any subframe S in the pluralityof subframes, the terminal device calculates a physical cell identifierand the S using a preset algorithm, to obtain a first value T1, wherethe TI is a value of four bits.

In this embodiment of the present invention, the physical cellidentifier and the number of the subframe may be first calculated usingthe preset algorithm, to obtain the first binary value T1 of four bits.

Specifically, a value TimeStamp[18:0] is first defined, which is abinary number and includes 19 bits, and the 19 bits are respectively 0or 1 from the zeroth bit to the 18^(th) bit. In this embodiment of thepresent invention, the value of the TimeStamp[18:0] is determined by thenumber of the subframe, that is, the super frame number, the framenumber, and the subframe number. Specifically, TimeStamp[18:0]=a superframe number×6×8+a frame number×6+a subframe number, so as to obtain abinary value TimeStamp[18:0] of 19 bits.

It should be noted that, in TimeStamp [18:0], for example,TimeStamp[2:0] represents a value whose zeroth bit (the zeroth digit isa units digit) to the second bit (the second bit is a hundreds digit)are respectively 0 or 1, TimeStamp[18:7] represents a value whoseseventh bit to the 18^(th) bit are respectively 0 or 1, and so on.

In this embodiment of the present invention, a binary constant PCI[3:0]of four bits (because a value of the PCI is 0 to 35 in the decimalsystem, the value of the PCI is 0 to 100011 in the binary system, andtherefore, a complete PCI includes 6 bits of 0 or 1; PCI[3:0] representsnumbers of the zeroth to the third bits of the PCI) may be added to a4-bit T0[3:0] (a value of T0[3:0] herein is TimeStamp[4:1]), and then, amod 16 operation is performed on the sum to obtain an output T1[3:0]. Itshould be noted that a purpose of performing the mod 16 operation is todisorder the numbers.

For example, an input physical cell is:

-   -   PCI[6:0]=111101, TimeStamp[18:0]=1001001011100010101,    -   then PCI[3:0]=1101, T0[3:0]=TimeStamp[4:1]=1010,    -   and then PCI[3:0]+T0[3:0]=10111, which is 23 in the decimal        system; after the mod 16 operation is performed, 7 is obtained,        and a binary value of 7 is 111. Therefore, T1[3:0]=0111.

2032. The terminal device performs bit reordering on values of four bitsof the T1 using the preset algorithm, to obtain a second value T2, wherethe T2 is a value of four bits.

In some feasible embodiments, optionally, the numbers may be furtherdisordered by performing the bit reordering.

Specifically, six control words B[0] to B[5] may be set. If a controlword is true, bits at corresponding locations are exchanged. As shownbelow, for example, if B[0] is true, two bits T1[0] and T1[1] areexchanged. If the control word is true, bits are exchanged.

Control word Value B[0] Xor (T1[0], T1[1]) B[1] Xor (T1[2], T1[3]) B[2]Xor (T1[0], T1[2]) B[3] Xor (T1[1], T1[3]) B[4] Xor (T1[0], T1[3]) B[5]Xor (T1[1], T1[2])

Then, a T2[3:0] obtained after the bit reordering is performed onT1[3:0] may be obtained.

For example, if T1[3:0]=0101, then:

Control T2 obtained by word Value changing a value of T1 B[0] = 1 Xor(T1[0], T1[1]) 0110 B[1] = 1 Xor (T1[2], T1[3]) 1010 B[2] = 0 Xor(T1[0], T1[2]) 1010 B[3] = 0 Xor (T1[1], T1[3]) 1010 B[4] = 1 Xor(T1[0], T1[3]) 0011 B[5] = 1 Xor (T1[1], T1[2]) 0110

Therefore, after all control words are changed, T2[3:0]=0110 isobtained.

2033. The terminal device calculates the T2 and the S using the presetalgorithm, to obtain a third value T3.

In some feasible embodiments, T2[3:0] output after the bit reordering isperformed is added to a constant C and A2[16:0] (a value of A2[16:0]herein is as follows: A2[2:0]=000). A2[14:3]=TimeStamp[16:5].A2[16:15]=xor (TimeStamp[18:17], PCI[5:4]), that is, A2[15]=xor(TimeStamp[17], PCI[4]), A2[16]=xor (TimeStamp[18], PCI[5]), and thenperform a mod 54 operation on the obtained result (in this embodiment,6×n=54, where n is a system configuration parameter), to obtain anoutput decimal value T3, where a value of T3 is 0 to 53.

For example:

  T 2[3 : 0] = 0110,  C = 1010,  TimeStamp[16 : 5] = 1001011011001110000,  TimeStamp[18 : 17] = 10,  PCI[5 : 4] = 11,  then  A 2[16 : 15] = 01,  A 2[14 : 3] =     TimeStamp[16 : 5] = 1001011011001110000,then  T 2[3 : 0] + C + A 2[16 : 0] = 0110 + 1010 + 1001011011001110000 = 1001011011010000000,and then, a decimal value is 308864, and T3=38 is obtained after mod 54is performed.

2034. The terminal device calculates the T3 and the virtual channelindex using the preset algorithm, to obtain a physical channelcorresponding to the virtual channel index on the S.

In this step, input parameters include T3, a configuration parameter nof the quantity of system channels, and a virtual channel index D, andoutput parameters include a channel index number and a sub-channel indexnumber.

Specifically, in this embodiment, mapping values that are in a one toone correspondence with the decimal data T3 are obtained according to acorresponding mapping rule. The following table is a mapping valuetable. The first 27 numbers in the mapping value table are even numbers,and the last 27 elements are odd numbers. For example, if T3=50 and n=9,a mapping value 45 may be obtained according to the mapping value table.

T3 Mapping value 0 0 1 2 . . . . . . 3n − 1 6n − 2 3n 1 3n + 1 3 . . . .. . 6n − 1 6n − 1

The method further disorders the values.

In this embodiment of the present invention, n is a channelconfiguration parameter of the quantity of system channels, and achannel number (Channel_index) and a sub-channel number(Sub-Channel_index) of a physical channel corresponding to an inputvirtual channel index are obtained, and are calculated using thefollowing formula:Channel_index=floor((mapping value+D)/6),Sub-channel_index=mod((mapping value+D),6).

If the obtained T3=4, the mapping value is 6, and is substituted intothe following formula to obtain:Channel_index=floor(mapping value/6)=1,Sub-channel_index=mod(mapping value,6)=0.

Then, the physical channel corresponding to the virtual channel index isobtained: the frame number of the physical channel is 1, and thesubframe number is 0.

It should be noted that a function of the floor function is “roundingdown”, that is, floor (x) is a maximum integer not greater than x. A modoperation, that is, a modulo operation, is an operation in which aremainder is obtained by dividing an integer x by another integer y inan integer operation, and a quotient of the operation is not considered.In the computer program design, there is a MOD operation, which means toobtain a remainder of a result after dividing one integer by anotherinteger. For example, 7 mod 3=1, because after 7 is divided by 3, aquotient is 2 and a remainder is 1. The remainder of 1 is a result ofthe MOD operation.

For example:

-   -   If T3=50, n=9, and D=15, the mapping value is 47,    -   then Channel_index=floor ((mapping value+D)/6)=floor        ((47+15)/6)=10,    -   Sub-channel_index=mod ((mapping value+D), 6)=mod ((47+15), 6)=2,    -   and therefore, the frame number of the physical channel is 10,        and the subframe number is 2.

204. For any virtual channel index D in the plurality of virtual channelindexes, the base station determines, based on the D, a physical channelcorresponding to the D on each of the plurality of subframes, where atleast two of the physical channels corresponding to the virtual channelindex on the plurality of subframes are different.

In this embodiment of the present invention, the base station and theterminal device may separately calculate, based on the virtual channelindexes, different physical channels corresponding to the virtualchannel index on all of the plurality of subframes. However, adifference lies in that: after selecting a virtual channel index, theterminal device only needs to calculate the physical channelcorresponding to the virtual channel index; and after generating aplurality of virtual channel indexes, the base station may calculateeach of the plurality of virtual channel indexes to obtain all thedifferent physical channels on a subframe group corresponding to theplurality of virtual channel indexes. Therefore, in some feasibleembodiments, for any virtual channel index D in the plurality of virtualchannel indexes and a subframe group Z corresponding to the D, the basestation determines, based on the D, a physical channel corresponding tothe D on any subframe in the Z.

Optionally, in the physical channels corresponding to the plurality ofvirtual channel indexes on the plurality of subframes, physical channelscorresponding to a same virtual channel index on two adjacent subframesare different. That is, optionally, after communication is completed oneach frame, the terminal device and the base station change the physicalchannel for communication.

Optionally, physical channels corresponding to any two of the pluralityof virtual channel indexes on the subframe are different. That is, on asame subframe, different virtual channel indexes are corresponding todifferent physical channels.

In some feasible embodiments, the obtained values may be calculatedusing the preset algorithm, to obtain the physical channel correspondingto the virtual channel index on the subframe; that is, the physicalchannel is in a one-to-one correspondence with the virtual channel indexon the subframe. In other words, within a given network capacity,different terminal devices may obtain different frequency hoppingchannels at a same fixed time, that is, orthogonality is met.Optionally, based on the subframe group corresponding to each of theplurality of virtual channel indexes, for any virtual channel index D inthe plurality of virtual channel indexes, the base station determines,based on the D, a physical channel corresponding to the D on eachsubframe in a subframe group corresponding to the D, where physicalchannels corresponding to any two of the plurality of virtual channelindexes on a same subframe are different.

In addition, randomicity may be implemented using the preset algorithm.The randomicity means that: A single terminal device obtains, at a fixedtime, a fixed corresponding frequency hopping channel; and as the timechanges, a time-based curve pattern of the frequency hopping channel israndom, and all channels have an equal probability of being selected;that is, in the physical channels corresponding to the plurality ofvirtual channel indexes on the plurality of subframes, physical channelscorresponding to a same virtual channel index on two adjacent subframesare different.

205. The terminal device communicates, on at least one of the pluralityof subframes, with the base station using the physical channelcorresponding to the virtual channel index.

In some feasible embodiments, after the terminal device determines thephysical channel corresponding to the selected virtual channel index oneach of the plurality of subframes, when determining to transmit data ona subframe, the terminal device may use the physical channel. Therefore,the terminal device may communicate, on at least one of the plurality ofsubframes, with the base station using the physical channel. It shouldbe noted that performing communication may refer to sending informationor receiving information, and this is not limited herein.

Referring to FIG. 4, an embodiment of the present invention furtherprovides a terminal device 400, where the terminal device 400 includes:

-   -   a transceiver unit 401, configured to receive a plurality of        virtual channel indexes from a base station, and specifically        configured to receive the plurality of virtual channel indexes        from the base station using a broadcast message or a dedicated        message; and    -   a processing unit 402, configured to: select a virtual channel        index from the plurality of virtual channel indexes, and        determine, based on the virtual channel index, physical channels        corresponding to the virtual channel index on a plurality of        subframes, where at least two of the physical channels        corresponding to the virtual channel index on the plurality of        subframes are different, and optionally, in the physical        channels corresponding to the plurality of virtual channel        indexes on the plurality of subframes, physical channels        corresponding to a same virtual channel index on two adjacent        subframes are different. Specifically, for the virtual channel        index and any subframe S in the plurality of subframes, a        physical cell identifier and the S are calculated using a preset        algorithm, to obtain a first value T1, where the TI is a value        of four bits; bit reordering is performed on values of four bits        of the T1 using the preset algorithm, to obtain a second value        T2, where the T2 is a value of four bits; the T2 and the S are        calculated using the preset algorithm, to obtain a third value        T3; and the T3 and the virtual channel index are calculated        using the preset algorithm, to obtain a physical channel        corresponding to the virtual channel index on the S.

The transceiver unit 401 is further configured to communicate, on atleast one of the plurality of subframes, with the base station using thephysical channel corresponding to the virtual channel index.

Referring to FIG. 5, an embodiment of the present invention furtherprovides a base station 500, where the base station 500 includes:

-   -   a transceiver unit 501, configured to send a plurality of        generated virtual channel indexes; and    -   a processing unit 502, configured to: for any virtual channel        index D in the plurality of virtual channel indexes, determine,        based on the D, a physical channel corresponding to the D on        each of the plurality of subframes, where at least two of the        physical channels corresponding to the D on different subframes        are different, and determine a virtual channel index selected by        a terminal device, where the virtual channel index is one of the        plurality of virtual channel indexes.

Optionally, the base station 500 may determine, based on each of theplurality of virtual channel indexes, a physical channel correspondingto each virtual channel index on a subframe, where the physical channelscorresponding to any two of the plurality of virtual channel indexes onthe subframe are different.

Optionally, based on a subframe group corresponding to each of theplurality of virtual channel indexes, for any virtual channel index D inthe plurality of virtual channel indexes, the base station 500determines, based on the D, a physical channel corresponding to the D oneach subframe in a subframe group corresponding to the D, where physicalchannels corresponding to any two of the plurality of virtual channelindexes on a same subframe are different.

Specifically, for the virtual channel index and any subframe S in theplurality of subframes, a physical cell identifier and the S arecalculated using a preset algorithm, to obtain a first value T1, wherethe TI is a value of four bits; bit reordering is performed on values offour bits of the T1 using the preset algorithm, to obtain a second valueT2, where the T2 is a value of four bits; the T2 and the S arecalculated using the preset algorithm, to obtain a third value T3; andthe T3 and the virtual channel index are calculated using the presetalgorithm, to obtain a physical channel corresponding to the virtualchannel index on the S.

The transceiver unit 501 is further configured to communicate, on atleast one of the plurality of subframes, with the terminal device usingthe physical channel corresponding to the virtual channel index.

Referring to FIG. 6, an embodiment of the present invention furtherprovides a base station 600, where the base station 600 includes:

-   -   a transceiver unit 601, configured to: send a plurality of        generated virtual channel indexes; and    -   send the plurality of generated virtual channel indexes using a        broadcast message or a dedicated message; and    -   a processing unit 602, configured to: determine, based on each        of the plurality of virtual channel indexes, a physical channel        corresponding to each virtual channel index on a subframe, where        the physical channels corresponding to any two of the plurality        of virtual channel indexes on the subframe are different, and        determine a virtual channel index selected by the terminal        device, where the virtual channel index is one of the plurality        of virtual channel indexes.

Optionally, for any virtual channel index D in the plurality of virtualchannel indexes, the base station 600 determines, based on the D, aphysical channel corresponding to the D on each of the plurality ofsubframes, where at least two of the physical channels corresponding tothe D on different subframes are different.

Optionally, based on a subframe group corresponding to each of theplurality of virtual channel indexes, for any virtual channel index D inthe plurality of virtual channel indexes, the base station 600determines, based on the D, a physical channel corresponding to the D oneach subframe in a subframe group corresponding to the D, where physicalchannels corresponding to any two of the plurality of virtual channelindexes on a same subframe are different.

Specifically, for the virtual channel index and any subframe S in theplurality of subframes, a physical cell identifier and the S arecalculated using a preset algorithm, to obtain a first value T1, wherethe TI is a value of four bits; bit reordering is performed on values offour bits of the T1 using the preset algorithm, to obtain a second valueT2, where the T2 is a value of four bits; the T2 and the S arecalculated using the preset algorithm, to obtain a third value T3; andthe T3 and the virtual channel index are calculated using the presetalgorithm, to obtain a physical channel corresponding to the virtualchannel index on the S.

The transceiver unit 601 is further configured to communicate, on thesubframe, with the terminal device using the physical channelcorresponding to the virtual channel index.

Referring to FIG. 7, an embodiment of the present invention furtherprovides a terminal device 700, where the terminal device 700 includes:

-   -   a transceiver 701 and a processor 702.

The transceiver 701 is configured to receive a plurality of virtualchannel indexes from a base station.

The processor 702 is configured to: select a virtual channel index fromthe plurality of virtual channel indexes, and determine, based on thevirtual channel index, physical channels corresponding to the virtualchannel index on a plurality of subframes, where at least two of thephysical channels corresponding to the virtual channel index on theplurality of subframes are different.

The transceiver 701 is further configured to communicate, on at leastone of the plurality of subframes, with the base station using thephysical channel corresponding to the virtual channel index.

Referring to FIG. 8, an embodiment of the present invention furtherprovides a base station 800, where the base station 800 includes:

-   -   a transceiver 801 and a processor 802.

The transceiver 801 is configured to send a plurality of generatedvirtual channel indexes.

The processor 802 is configured to: for any virtual channel index D inthe plurality of virtual channel indexes, determine, based on the D, aphysical channel corresponding to the D on each of the plurality ofsubframes, where at least two of the physical channels corresponding tothe D on different subframes are different, and determine a virtualchannel index selected by a terminal device, where the virtual channelindex is one of the plurality of virtual channel indexes.

The transceiver 801 is further configured to communicate, on at leastone of the plurality of subframes, with the terminal device using thephysical channel corresponding to the virtual channel index.

Referring to FIG. 9, an embodiment of the present invention furtherprovides a base station 900, where the base station 900 includes:

-   -   a transceiver 901 and a processor 902.

The transceiver 901 is configured to send a plurality of generatedvirtual channel indexes.

The processor 902 is configured to: determine, based on each of theplurality of virtual channel indexes, a physical channel correspondingto each virtual channel index on a subframe, where the physical channelscorresponding to any two of the plurality of virtual channel indexes onthe subframe are different, and determine a virtual channel indexselected by the terminal device, where the virtual channel index is oneof the plurality of virtual channel indexes.

The transceiver 901 is further configured to communicate, on thesubframe, with the terminal device using the physical channelcorresponding to the virtual channel index.

It may be understood by a person skilled in the art that, for thepurpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and unit, refer to acorresponding process in the foregoing method embodiments, and detailsare not described herein again.

In the several embodiments provided in this application, it should beunderstood that the disclosed system, apparatus, and method may beimplemented in other manners. For example, the described apparatusembodiment is merely an example. For example, the unit division ismerely logical function division and there may be other division inactual implementation. For example, a plurality of units or componentsmay be combined or integrated into another system, or some features maybe ignored or not performed. In addition, the displayed or discussedmutual couplings or direct couplings or communication connections may beimplemented using some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected based on actualrequirements to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of the presentinvention may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit. The integrated unit may be implemented in a form ofhardware, or may be implemented in a form of a software functional unit.

When the integrated unit is implemented in the form of a softwarefunctional unit and sold or used as an independent product, theintegrated unit may be stored in a computer-readable storage medium.Based on such an understanding, the technical solutions of the presentinvention essentially, or the part contributing to the current system,or all or some of the technical solutions may be implemented in the formof a software product. The software product is stored in a storagemedium and includes several instructions for instructing a computerdevice (which may be a personal computer, a server, or a network device)to perform all or some of the steps of the methods described in theembodiments of the present invention. The foregoing storage mediumincludes: any medium that can store program code, such as a USB flashdrive, a removable hard disk, a read-only memory (ROM), a random accessmemory (RAM), a magnetic disk, or an optical disc.

The foregoing embodiments are merely intended for describing thetechnical solutions of the present invention, but not for limiting thepresent invention. Although the present invention is described in detailwith reference to the foregoing embodiments, a person of ordinary skillin the art should understand that they may still make modifications tothe technical solutions described in the foregoing embodiments or makeequivalent replacements to some technical features thereof, withoutdeparting from the spirit and scope of the technical solutions of theembodiments of the present invention.

What is claimed is:
 1. A non-transitory computer-readable medium storinginstructions that, when executed by one or more processors, cause theone or more processors to perform operations comprising: receiving, froma base station, a plurality of virtual channel indexes; selecting avirtual channel index from the plurality of virtual channel indexes;determining, based on the virtual channel index, physical channelscorresponding to the virtual channel index on a plurality of subframes,wherein at least two of the physical channels corresponding to thevirtual channel index on the plurality of subframes are different; andcommunicating with the base station using a physical channelcorresponding to the virtual channel index on at least one of theplurality of subframes.
 2. The non-transitory computer-readable mediumaccording to claim 1, wherein determining the physical channelscorresponding to the virtual channel index on the plurality of subframesis further based on one or any combination of the following: a physicalcell identifier; a configuration parameter of a quantity of systemchannels; a frame number; a subframe number; or a super frame number. 3.The non-transitory computer-readable medium according to claim 1,wherein in the physical channels corresponding to the plurality ofvirtual channel indexes on the plurality of subframes, physical channelscorresponding to a same virtual channel index on two adjacent subframesare different.
 4. The non-transitory computer-readable medium accordingto claim 1, wherein the operations further comprise receiving theplurality of virtual channel indexes from the base station using abroadcast message or a dedicated message.
 5. The non-transitorycomputer-readable medium according to claim 1, wherein communicatingwith the base station using the physical channel corresponding to thevirtual channel index on the at least one of the plurality of subframescomprises communicating with the base station using the physical channelcorresponding to the virtual channel index on all of the plurality ofsubframes.
 6. A non-transitory computer-readable medium storinginstructions that, when executed by one or more processors, cause theone or more processors to perform operations comprising: sending aplurality of generated virtual channel indexes; determining, based oneach of the plurality of virtual channel indexes, a physical channelcorresponding to each virtual channel index on a subframe, wherein thephysical channels corresponding to any two of the plurality of virtualchannel indexes on the subframe are different; determining a virtualchannel index selected by a terminal device, wherein the virtual channelindex is one of the plurality of virtual channel indexes; andcommunicating on a plurality of subframes with the terminal device usingthe physical channel corresponding to the virtual channel index.
 7. Thenon-transitory computer-readable medium according to claim 6, whereinthe operations further comprise: determining, for each virtual channelindex of the plurality of virtual channel indexes, a subframe groupcorresponding to the virtual channel index; and for any virtual channelindex D in the plurality of virtual channel indexes, determining, basedon the D, a physical channel corresponding to the D on each subframe ina subframe group Z corresponding to the D, wherein physical channelscorresponding to any two of the plurality of virtual channel indexes ona same subframe are different.
 8. The non-transitory computer-readablemedium according to claim 6, wherein for any virtual channel index D inthe plurality of virtual channel indexes, at least two of the physicalchannels corresponding to the D on different subframes are different. 9.The non-transitory computer-readable medium according to claim 6,wherein in the physical channels corresponding to the plurality ofvirtual channel indexes on the plurality of subframes, physical channelscorresponding to a same virtual channel index on two adjacent subframesare different.
 10. The non-transitory computer-readable medium accordingto claim 6, wherein, for any virtual channel index D in the plurality ofvirtual channel indexes, determining the physical channel correspondingto the D on any subframe in a subframe group Z corresponding to the D isfurther based on one or any combination of the following: a physicalcell identifier; a configuration parameter of a quantity of systemchannels; a subframe number; or a super frame number.
 11. Thenon-transitory computer-readable medium according to claim 10, whereinthe operations further comprise sending, to the terminal device, one orany combination of the following: the physical cell identifier; theconfiguration parameter of the quantity of system channels; the subframenumber; or the super frame number.
 12. The non-transitorycomputer-readable medium according to claim 6, wherein the operationscomprise sending the plurality of generated virtual channel indexesusing a broadcast message or a dedicated message.
 13. The non-transitorycomputer-readable medium according to claim 6, wherein: sending theplurality of generated virtual channel indexes comprises sending theplurality of virtual channel indexes to a plurality of terminal devices,the terminal device being one of the plurality of terminal devices; andthe operations further comprise communicating on at least one subframeof the subframes with the terminal device and at least one otherterminal device of the plurality of terminal devices.
 14. An apparatus,comprising: a transceiver configured to send a plurality of generatedvirtual channel indexes; and at least one processor configured to:determine, based on each of the plurality of virtual channel indexes, aphysical channel corresponding to each virtual channel index on asubframe, wherein the physical channels corresponding to any two of theplurality of virtual channel indexes on the subframe are different; anddetermine a virtual channel index selected by a terminal device, whereinthe virtual channel index is one of the plurality of virtual channelindexes; wherein the transceiver is further configured to communicate,on a plurality of subframes, with the terminal device using the physicalchannel corresponding to the virtual channel index.
 15. The apparatusaccording to claim 14, wherein the at least one processor is configuredto: determine, for each virtual channel index of the plurality ofvirtual channel indexes, a subframe group corresponding to the virtualchannel index; and for any virtual channel index D in the plurality ofvirtual channel indexes, determine, based on the D, a physical channelcorresponding to the D on each subframe in a subframe group Zcorresponding to the D, wherein physical channels corresponding to anytwo of the plurality of virtual channel indexes on a same subframe aredifferent.
 16. The apparatus according to claim 14, wherein for anyvirtual channel index D in the plurality of virtual channel indexes, atleast two of the physical channels corresponding to the D on differentsubframes are different.
 17. The apparatus according to claim 14,wherein in the physical channels corresponding to the plurality ofvirtual channel indexes on the plurality of subframes, physical channelscorresponding to a same virtual channel index on two adjacent subframesare different.
 18. The apparatus according to claim 14, wherein, for anyvirtual channel index D in the plurality of virtual channel indexes,determining the physical channel corresponding to the D on any subframein a subframe group Z corresponding to the D is further based on one orany combination of the following: a physical cell identifier; aconfiguration parameter of a quantity of system channels; a subframenumber; or a super frame number.
 19. The apparatus according to claim14, wherein the transceiver is further configured to send the pluralityof generated virtual channel indexes using a broadcast message or adedicated message.
 20. The apparatus according to claim 14, wherein:sending the plurality of generated virtual channel indexes comprisessending the plurality of virtual channel indexes to a plurality ofterminal devices, the terminal device being one of the plurality ofterminal devices; and the transceiver is further configured tocommunicate on at least one subframe of the subframes with the terminaldevice and at least one other terminal device of the plurality ofterminal devices.